Diesel engines



W. J. SILVA DIESEL ENGINES May 29, 1956 3 Sheets-Sheet 1 Filed NOV. 9,1953 ATTORNEYS.

May 29, 1956 w. J. SILVA 2,747,557

' DIESEL ENGINES Filed Nov. 9. 1953 s Sheets-Sheet 2 INVENT OR i lFliz'a'm JSZZ a BY @M ATTORNEYS United States Patent DIESEL ENGINESWilliam J. Silva, New Orleans, La.

Application November 9, 1953, Serial No. 390,853

6 Claims. (Cl. 12332) This invention relates to internal combustionengines of the diesel type and more particularly to a two-cycle dieselengine.

The principal object of the invention is to provide an improved dieselengine which will be more simple, more compact and lighter than priordiesel engines of comparable horse power.

A further object is to provide an improved diesel engine which willeliminate the customary cam shaft, timing gears, valves, rocker arms andpush rods.

A still further object is to provide the crank shaft, rather than aseparate cam shaft, with the necessary cams for operating the fuelinjectors.

Another object is to provide an improved diesel engine which willoperate to equal advantage in either direction, primarily for marineuse.

Another object of the invention is to provide the crank shaft with twosets of injector operating cams, one set being operable when the engineis driven in one direction and the other set being operable when theengine is driven in the other direction, one set or the other beingautomatically brought into operation according to the direction in whichthe engine is started.

Yet another object of the invention is to provide a sleeve carrying bothsets of cams and shiftable axially to bring one set or the other intoposition for operation, A

the sleeve being threaded on an extension of the crank shaft and beingaxially shifted by the screw threads in one direction or the other,according to the direction in which the engine is turned over to effectstarting.

A still further object of the invention is to provide a novel scavengingblower for the engine cylinders which will operate to equal advantageregardless of the direction in which the engine is driven.

With the above and other objects in view that will become apparent asthe nature of the invention is better understood, the same consists inthe novel form, con1- bination and arrangement of parts hereinafter morefully described, shown in the accompanying drawings, and claimed.

In the drawings:

Fig. l is a longitudinal sectional view through the improved engine;

Fig. 2 is a transverse sectional view on line 22 of Fig. 1, the blowerbeing shown principally in elevation;

Fig. 3 is an enlarged vertical sectional view showing the blower; and

Fig. 4 is an enlarged side elevation partly in section showing the camsleeve and associated parts.

A four-cylinder engine is shown but the invention is equally adaptableto a six or eight cylinder construction. The four cylinders are denotedby the numerals 1, 2, 3, and 4, with cylinder 1 at the flywheel end ofthe engine. These cylinders are within a block 5 and a head 6 is securedto said block. This head carries fuel injection spray nozzles 7 but novalves nor valve actuating rockers.

The pistons of the four cylinders are denoted at 8 and their connectingrods at 9. These rods are connected to "ice the four crank pins 10 ofthe crank shaft 11, and said crank pins are spaced apart 90. In Fig. 1,the pin 10 under cylinder 1 is at upper dead center, the pin undercylinder 4 is at lower dead center, the pin under cylinder 2 is behindthe crank shaft axis, and the pin under cylinder 3 is in front of saidaxis. With this 90 crank pin spacing, the firing order of the cylindersis 134-2.

The crank shaft 11 is mounted in main bearings 12 in a suitable crankcase 13, one end 13 of said crank case being extended beyond the block 5and having a bearing 14 aligned with the main bearings 12. One end 15 ofa crank shaft extension 16 passes through this bearing and is providedwith a pulley 17 for driving a generator and water pump. The other endof the extension16 is provided with a flange 18 bolted at 19 to a flange20 on one end of the crank shaft body, said extension 16 thus formingvirtually a part of the crank shaft. The other end of this crank shafthas a flywheel 21 and said flywheel carries the usual ring gear 22 forstarting purposes. Two starters are preferably used, one to start in onedirection and the other to start in the other direction. These startersare indicated in Fig. 2 by the broken lines 23.

On the crank shaft extension 16, there is a cam sleeve 24 for actuatinginjector pumps 25 from which fuel lines 26 extend to the fuel injectionspray nozzles 7. The pumps 25 are fed by a transfer pump 27. All of thepumps 25 and 27 are mounted on the top plate 28 of the crank caseextension 13 and said pumps include plungers 25 and 27*, respectively.These plungers are camactuated and spring-returned. The cam for thetransfer pump 27 is on the end 15 of the crank shaft extension 16 and isdenoted at 29, said cam being on a flange 30 of said end 15. The camsfor the injector pumps 25 are on the cam sleeve 24 and will be laterdescribed.

The crank shaft extension 16 is provided with a coarse screw thread 31and the cam sleeve 24 has an internal thread 32 engaging said thread 31as illustrated in Fig. 4. This cam sleeve is axially shiftable from theposition shown, against flange 30, to a position against flange 18 andthe shifting of said sleeve is eflected by the coacting screw threads31, 32 according to the direction in which the crank shaft is initiallyrotated to start the engine. During such initial crank shaft rotation,the cam sleeve 24 is held against turning with the crank shaft by theresistance of the various pumps and consequently said sleeve will beaxially shifted to the limit allowed by the flange 18 or 30 as the casemay be. As soon as the sleeve abuts either of these stop flanges 18, 30,said sleeve rotates bodilywith the crank shaft 11 and operates thetransfer pump 27 and the injector pumps 25, with the result that theengine will start firing and continue to operate, the cylinder beingscavenged and supplied with air by means yet to be described.

The flange 18 and adjacent end of the cam sleeve 24 preferably haveteeth 18 to mesh when said flange 18 and said cam sleeve abut. Similarlythe flange 30 and adjacent end of the sleeve 24, preferably have teeth30 for the same purpose. The teeth 18 or 36* drive the sleeve 24 andprevent the screw threads 31, 32 from tightly jamming said sleeveagainst either flange.

The cam sleeve 24 has four peripheral zones 1*, 2 3 4 allotted to thecylinders 1, 2, 3, 4, respectively. For better understanding, thosezones have been defined by dot-and-dash lines. The zone 1 has one cam 1which operates the injector pump for cylinder 1 for left hand operationof the engine, as indicated by the arrows in Figs. 1 and 4. This zone 1also has a cam 1 for operating the injector pump of cylinder 1 for righthand operation of the engine. These two cams 1 and 1 are spaced apartand are offset longitudinally of the sleeve 24 to allow only cam 1 tooperate the injector pump when said sleeve 24 occupies one position asin Figs.

V ence of the rotor 43.

'Two air inlet passages 46 and 47 extend from the air 7' 3 V l and 4 andto allow only the cam 1 to operate said injector pump when said sleeveis shifted to its other 7 position.

' positioned'as described in connection with the cams 1 and 1 of zone 1The cams 1 2 3 and 4 are of course spaced 90 apart and the .same is trueof the cams 1, 2,3, and

With the various cams in the positions shown, the engine is turning tothe left (as viewed from the flywheel end). The piston of cylinder 1 ison top dead center and thencam 1 is. operating the injector pump of saidcylinder 1 to fire it. Cyl'inder 2 has just fired and the injector pumpcam 2 allotted to this cylinder 2 is ninety degrees past dead center.The piston'of cylinder 3 is ascending on its compression stroke and thecam 3 is 90 before top dead center. Cylinder 4 is exhausting and thecorresponding cam 4 is 180 before top dead center.

Each of the cylinders is provided with a piston-controlled exhaust port33 as shown in Fig. 2 and with an air admission port 34. Air is suppliedtothe cylinders through the ports 34 by means of a blower 35 which isdriven by a silent-chain-and-sprocket drive 36 from the crankshaft. Justafter any piston uncovers the exhaust port 33 and permits exhaust gasesto escape, the piston uncovers the air admission port 34 and the blower35 forces scavenging air into and across the cylinder. As the pistonascends and covers the ports 33 and 34, it compresses air in readinessfor injection of fuel and when this injection occurs the cylinder fires.

The blower 15 may be of any type which will operate regardless of thedirection in which it is driven, but this characteristic is essentialunless complicated and expensive blower reversing means is provided, assaid blower will be driven in one direction during left hand rotation ofthe engine and reversely during right hand rotation.

The preferred blower construction is shownin Fig. 3. A casing 37 isprovided having an air inlet 38 and in the casing 37 and coa'cts withabout half the circum- V fer'ence of rotor 42'. A second substantiallysemi-circular wall 45 similarly coacts with about half thecircumferinlet'38 past the ends of the wall 44- to conduct air to the;rotors regardless of .the direction in which they rotate.

Only one of these passages 46, 47 functions during right hand rotationand only the other during left hand rotation/These two passages 46 and47 have check valves 7 46 and 47 respectively, .to insure this, both ofthese valves being of suction-opened and pressure-closed form.

this, both'of said valves 48 and '49? being of pressureopened andsuction-closed form. v

In Fig. 3, the suction created by the rotating rotors 4 2, 43 'at theintake side of the-blower 35 is holding.

check valve 46 closed. At the same time, the pressure created by therotors at the output side of the blower is holding the check valve 47closed and the valve 49*- open. Consequently, with the rotors turning asindi cated by the arrows thereon, theair will flow as indicated by theother arrows. When the engine is reversely driven, however, and therotors consequently turn in the other direction, the valve 47 opens andvalve 46 closes, causing the air inlet passage 47 to function. At thesame time, valve 48 opens and valve 49 'closes, causing the airdischarge passage 48 to function. Thus, the blower will operate toperform its functions whether the engine be turning in one direction orthe other.

It will be seen from the foregoing that a novel construction has beenprovidedv for attaining thedesired ends, but it is to be understoodthat. variations may well be made. For example while a reversible enginehas been shown requiring two sets of cams, it will be clear that for anengine to rotate only in one direction, only one set of cams would berequired. In that case, a cam member corresponding. to sleeve 24 wouldbe directly near said crank shaft, tubes connecting said injector pumps'withsaid injector spray nozzles respectively, a cam sleeve surrounding aportion of said crank shaft, said cam sleeve having one set of cams foroperating said'injector pumps when the engine is to rotate to the right,said cam sleeve having a second set of cams for operating said injectorpumps when the engine is to rotate to the left, said sleeve beingaxially shiftable in response to drag forces when the crankshaft isturned over for starting in one direction to one position in which saidone set of cams becomes effective and being axially shiftable inresponse to dragforces when the crank shaft is turned over for startingin the other direction to a second position in which said second set ofcams becomes effective, stop means for limiting the axial movement ofsaid sleeve when it reaches either of said positions. 7

2. A structure as spccifiedin claim l, saidsleeve having a threadedconnection with said crank-shaft between said stop means.v

3. A structure as specified in claim 1, said sleeve having a threadedconnection with said portion of said crankshaft between said stop means,said stop means comprising stop shoulders on said portion of saidcrankshaft to be struck by the ends of said sleeve. 7

4. A structure asspecifiedin claim 1, said sleeve having a threadedconnection with said portion of said crankshaft between said stop means,said stop means comprising stop shoulders on said portion of. said crankshaft to be struck by the ends of said sleeve, said step shoulders andsleeve ends having coacting sleeve driving teeth.

5. A structure as specified in claim 1, said blower being of a typewhich will function regardless of the, direction in which'said blower isdriven.

6. A structure as specified in claim 1', said blower comprising a casinghaving an air inlet and an air outlet, two

'coacting rotors in" said casing, said rotors having intermeshing lobes,one substantially semicircular wall in said casing and engaging theperiphery of one of said rotors, a second substantially semi-circularwall in said casing and engaging the periphery of the otherrotor, theends of said one wall being spaced from the ends of said second wall, 7

two air inlet passages extending from said air inlet to the ends of saidone wall, respectively, two air discharge passages extending from theends of said second wall respectively to said air outlet, two suctionopened pressureclosed check valves for said two air inlet passagesrespectively, and two pressure-opened suction-closed check valves forsaid two air discharge valves respectively whereby the blower willreceive air from said air inlet and discharge air through said airoutlet regardless of the 5 direction in which said rotors are driven.

References Cited in the file of this patent UNITED STATES PATENTS354,063 Johnson Dec. 7, 1886 10 6 Lepley Mar. 11, 1919 Pielstick Apr. 1,1930 Gosslau Oct. 10, 1933 Martin et al Mar. 20, 1934 Reiland Nov. 28,1944 Yingling Jan. 29, 1946 Froehlich Feb. 5, 1946 FOREIGN PATENTS ItalyJan. 23, 1939

